//
// Manta - Structural Variant and Indel Caller
// Copyright (c) 2013-2019 Illumina, Inc.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
//
//

/// \file
/// \author Chris Saunders
///

#include <random>

template <typename T, typename RNG>
void SampleVector<T, RNG>::push(const T& val)
{
  if (_inputCount < _data.size()) {
    // initial fill of the reservoir array is deterministic:
    _data[_inputCount] = val;
  } else {
    // replace elements with gradually decreasing probability:
    std::uniform_int_distribution<unsigned> rdist(0, _inputCount);
    const unsigned                          rval(rdist(_rng));

    if (rval < _data.size()) {
      _data[rval] = val;
    }
  }
  _inputCount++;
}
